Apparatus and method for venting and sealing a portable communication device

ABSTRACT

An improved venting and sealing assembly for a portable communication device is provided. The venting and sealing assembly is formed of a housing enclosure having a walled aperture with a bottom surface and an offset through-hole passing therethrough. A flexible substrate having a vent hole is coupled to the housing enclosure across the walled aperture such that the vent hole is offset from the offset through-hole. A breathable membrane is coupled across the vent hole of the flexible substrate. A rigid plate having an opening is coupled to the breathable membrane, the opening of the rigid plate being aligned with the vent hole of the flexible substrate. A closed-loop sealing rib is formed around the vent hole of the flexible substrate and/or upon the bottom surface of the walled aperture of the housing enclosure. The assembly provides a vent path and a self-sealing enclosure.

FIELD OF THE INVENTION

The present invention relates generally to venting and sealingassemblies and more particularly to venting and sealing a portablecommunication device.

BACKGROUND

Today's portable communication devices are challenged to incorporate anincreasing number of features into a small form factor. Portablecommunication devices, such as portable radio products utilized in thepublic safety market, are further challenged by having to operate undersevere environmental conditions where maintaining appropriate ventingand sealing of the product is imperative to proper operation of theradio. The venting and sealing of the ruggedized product needs to beoperational at predetermined pressure ratings not typically associatedwith off-the shelf consumer type products. For example, ever-increasingwater submersion ratings for ruggedized products present venting andsealing challenges.

Many of today's typical venting approaches have drawbacks making themunsuitable for the portable radio public safety environment. Forexample, air hole structures which are completely passive for ventingoffer no sealing capability and thus no protection in wet environments.Products which utilize membranes that must be removed for test purposesface issues with improper re-alignment and large venting structures takeup too much real estate and face potential leak issues.

Accordingly, it would be desirable to have an improved venting andsealing assembly. An improved venting and sealing assembly that couldaddress the above aforementioned problems would be of particular benefitfor incorporation into a portable communication device utilized in thepublic safety environment.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying figures where like reference numerals refer toidentical or functionally similar elements throughout the separate viewsand which together with the detailed description below are incorporatedin and form part of the specification, serve to further illustratevarious embodiments and to explain various principles and advantages allin accordance with the present invention.

FIG. 1A is a partial cutaway view of a venting and sealing assemblyhaving an open vent path in accordance with an embodiment.

FIG. 1B is a partial cutaway view of the venting and sealing assembly ofFIG. 1B having a sealed vent path closed in accordance with anembodiment.

FIG. 2 is a partial cutaway isometric view of a portable radioincorporating a venting and sealing assembly in accordance with anembodiment.

FIG. 3 is a partial cutaway view of a venting and sealing assemblyhaving a vent path in accordance with another embodiment.

FIG. 4 is a partial cutaway view of a venting and sealing assemblyhaving a vent path in accordance with another embodiment.

Skilled artisans will appreciate that elements in the figures areillustrated for simplicity and clarity and have not necessarily beendrawn to scale. For example, the dimensions of some of the elements inthe figures may be exaggerated relative to other elements to help toimprove understanding of embodiments of the present invention.

DETAILED DESCRIPTION

Before describing in detail embodiments that are in accordance with thepresent invention, it should be observed that the embodiments resideprimarily in a venting and sealing assembly. The venting and sealingassembly can be incorporated into a communication device, such as aportable radio or remote speaker microphone, and is particularly wellsuited to portable communication devices intended for the public safetyenvironment.

Briefly, a housing enclosure of the device provides an internal walledaperture providing a vent path formed therein passing from an interiorof the housing to an exterior of the housing. A passive pressureequalization vent, formed of a breathable membrane, is mounted to anactive sealing valve mechanism. The active sealing valve mechanismcomprises a moveable substrate, which may be formed of a flexible orrigid material, which automatically seals to the internal walledaperture or vent path to create a pressure sensitive barrier in responseto predetermined changes in pressure. An internal sealing rib surfacelimits travel of the moveable substrate within the internal walledaperture. The venting and sealing assembly takes up little space makingit well suited for devices having limited space constraints.

Accordingly, the components have been represented where appropriate byconventional symbols in the drawings, showing only those specificdetails that are pertinent to understanding the embodiments of thepresent invention so as not to obscure the disclosure with details thatwill be readily apparent to those of ordinary skill in the art havingthe benefit of the description herein.

In this document, relational terms such as first and second, top andbottom, and the like may be used solely to distinguish one entity oraction from another entity or action without necessarily requiring orimplying any actual such relationship or order between such entities oractions. The terms “comprises,” “comprising,” or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus. An element preceded by “comprises . . . a” does not, withoutmore constraints, preclude the existence of additional identicalelements in the process, method, article, or apparatus that comprisesthe element.

FIGS. 1A and 1B show a partial cutaway view of a venting and sealingassembly 100 in accordance with an embodiment. FIG. 1A shows an openvent path 102 in accordance with an embodiment, while FIG. 1B shows asealed vent path 104 being established in accordance with an embodiment.Assembly 100 comprises a housing enclosure 106 having a walled aperture108 with a bottom surface 110 and an offset through-hole 112 passingtherethrough. The assembly 100 further comprises a flexible substrate114 having a vent hole 116, the flexible substrate being coupled to thehousing enclosure 106 across the walled aperture 108. In accordance withan embodiment, the vent hole 116 of the flexible substrate 114 is offsetfrom the offset through-hole 112 of the bottom surface 110 of the walledaperture 108. The flexible substrate 114 may be formed of a siliconerubber sheet, or suitable air impermeable and water impermeable materialthat allows for flexible vertical movement. In the embodiment of FIGS.1A and 1B, a closed-loop sealing rib 124 is integrated around the venthole 116 of the flexible substrate 114.

In accordance with an embodiment, a breathable membrane 118 is coupledacross the vent hole 116 of the flexible substrate 114. The breathablemembrane 118 may be formed of material having air breathable but waterrestrictive properties, such as expanded Polytetrafluoroethylene (PTFE)material, for example expanded TEFLON, or other appropriate materialhaving air breathable and water restrictive properties. For example,membranes made of air-permeable and water-impermeable material, such asGore-Tex® material available from W. L Gore, are suitable. For thepurposes of this application, the breathable membrane 118 is consideredto be air-permeable and water-impermeable. The breathable membrane 118is adhesively coupled to the flexible substrate 114, such that membranecovers the vent hole 116 providing a barrier to water while allowing airto pass through.

In accordance with an embodiment, a rigid plate 120, having an opening122, is coupled to the breathable membrane 118, such that the opening122 of the rigid plate 120 is aligned with the vent hole 116 of theflexible substrate 114. The rigid plate 120 is formed of a stiffenermaterial such as rigid plastic, for example stamped or molded plastic,to provide sufficient stiffness to back up the flexible substrate 114over a closed-loop sealing rib 124.

During normal operation, the vent path 102 is formed through the offsetthrough-hole 112 of the housing enclosure 106, the walled aperture 108of housing enclosure 106, the vent hole 116 of the flexible substrate114, and the breathable membrane 118 coupled across the vent hole 116 ofthe flexible substrate 114 and the opening 122 of the rigid plate 120.The breathable membrane 118 coupled across the vent hole 116 behaves asa passive pressure equalization vent.

In accordance with an embodiment, the rigid plate 120 provides anexternal rigid surface area that is larger than the internal sealingarea created by the closed-loop sealing rib 124 thereby providingadequate sealed backup. The rigid plate 120 provides gain in the valvesealing pressure to securely isolate the breathable membrane 118 or inother words isolates the passive pressure equalization vent.

In accordance with other embodiments, the closed-loop sealing rib 124may formed upon at least one of: the flexible substrate 114, around thevent hole 116 and/or upon the bottom surface 110 of the walled aperture108 of the housing enclosure 106. In the embodiment of FIGS. 1A and 1B,the closed-loop sealing rib 124 is a closed-loop compliant seal ribintegrated around the vent hole 116 of the flexible substrate 114.

In FIG. 1B, the flexible substrate 114 having a compliant closed-loopsealing rib 124 integrated thereon is shown establishing a seal againstthe bottom surface 110 of walled aperture 108. In this view, theflexible substrate 114 has collapsed in response to a predeterminedchange in pressure sensed through the breathable membrane 188 at venthole 116. The sealing shown in FIG. 1B isolates the breathable membrane118. The closed-loop sealing rib 124 limits travel of the flexiblesubstrate 114. In accordance with an embodiment, the flexible substrate114 operates as an active sealing valve mechanism to form a waterproofbarrier over the walled aperture 108 of the housing enclosure 106.

FIG. 2 is a partial cutaway isometric view of a portable communicationdevice, shown here as a portable radio 200, incorporating a venting andsealing assembly formed in accordance with an embodiment. Portable radio200 comprises a housing 206 having an interior walled aperture 208through which a vent path 202 vents and seals from an interior 260 ofthe housing 206 to an exterior 250.

In accordance with an embodiment, a moveable substrate 214 having a venthole 216 operates as an active sealing valve mechanism. The moveablesubstrate 214 is mounted to the housing 206 such that the vent hole 216opens into the interior walled aperture 208. A passive pressureequalization vent, formed of a breathable membrane 218, covers the venthole 216 across the moveable substrate 214. In accordance with theembodiment, the active sealing valve mechanism (moveable substrate 214)and passive equalization vent (breathable membrane 218) automaticallyseal to the interior walled aperture 208 to create a pressure sensitivebarrier—in response to predetermined changes in pressure.

In FIG. 2, the moveable substrate 214 comprises a flexible substratecoupled to the housing 206, wherein the internal sealing rib 224 isformed as part of an interior surface of a moveable substrate 214. Aninternal sealing rib 224 limits travel of the moveable substrate 214within the interior walled aperture 208.

The internal sealing rib 224, as will be shown in the embodiment of FIG.3, may also be formed on a bottom sealing surface of the internal walledhousing. In yet another alternative embodiment, which will be describedlater in conjunction with FIG. 4, the moveable substrate may comprise arigid substrate coupled to the housing with flexure bellows, and theinternal rib sealing surface comprises a flexible substrate with acompliant sealing rib forming a base of the walled aperture.

Accordingly, the outer moveable substrate may be formed of either aflexible material or a rigid material. The exterior moveable substrateof the various embodiments gets pulled into the housing aperture inresponse to predetermined changes in pressure thereby forming a sealwith the closed loop sealing rib. The various embodiments provide for anactive sealing valve mechanism and passive equalization vent whichautomatically seals to an internal walled aperture to create a pressuresensitive barrier.

Changes in pressure can be caused by a variety of factors such as,including but not limited to: moving from a warm environment to a coldenvironment; from a cold environment to a warm environment;inefficiencies of internal components RF and audio power amplifiers(PAs) causing the air sealed within the enclosure to be heated andexpand; long duration, maximum rate free-fall of high altitude lowopening (HALO); rapid climbing maneuvers in an un-pressurizedhelicopter; rapid environmental decompression (for example, a cabinairliner).

An advantage associated with the various embodiments is that thebreathable membrane remains present both during factory testing of theventing and sealing assembly of the portable radio and after shipment ofthe portable radio, thereby eliminated any alignment issues associatedwith removal and replacement of a membrane for test purposes.

FIG. 3 is a partial cutaway view of a venting and sealing assembly 300in accordance with another embodiment. Assembly 300 is similar toassembly 100 in that the assembly comprises housing enclosure 106 havinga walled aperture 108 with bottom surface 110 and offset through-hole112 passing therethrough. The assembly 300 further comprises flexiblesubstrate 114 having vent hole 116, the flexible substrate being coupledto the housing enclosure 106 across the walled aperture 108. Inaccordance with the embodiment, the vent hole 116 of the flexiblesubstrate 114 is offset from the offset through-hole 112 of the walledaperture's bottom surface 110. The breathable membrane 118 is coupledacross the vent hole 116 of the flexible substrate 114. The rigid plate120, having opening 122, is coupled to the breathable membrane 118, suchthat the opening 122 of the rigid plate is aligned with the vent hole116 of the flexible substrate 114.

In accordance with this FIG. 3 embodiment, assembly 300 comprises aclosed-loop sealing rib 324 formed as a hard-stop closed loop sealingrib integrated as part of the bottom surface 110 of the walled aperture108 of the housing enclosure 106.

Similarly to assembly 100, in assembly 300 the vent path is providedthrough the offset through-hole 112 of the housing enclosure 106, thewalled aperture 108 of housing enclosure 106, the vent hole 116 of theflexible substrate 114, the breathable membrane 118 coupled across thevent hole 116 of the flexible substrate 114 and the opening 122 of therigid plate 120. However, in accordance with the embodiment of FIG. 3,as the flexible substrate 114 collapses, under predetermined pressure,into the walled aperture 108 against the bottom surface 110, thehard-stop closed-loop sealing rib 324 of the bottom surface 110 withinthe walled aperture 108 seals against the flexible substrate 114 therebyisolating the breathable membrane 118. The closed-loop rib 324 limitstravel of the flexible substrate 114. The use of the hard-stopclosed-loop sealing rib 324 on the stationary, bottom surface 110 forsealing purposes still results in an isolated breathable membrane 118.

In another embodiment also shown in FIG. 3, closed-loop sealing rib 124(shown in dashed lines) and closed-loop sealing rib 324 may located onopposite upper and lower interior surfaces and slightly offset from eachother, for a dual rib approach if desired. Thus, the closed loop sealingrib can be incorporated on one or both of the interior surfaces (i.e.interior bottom surface 110 and/or interior of surface of flexiblesubstrate 114). For example, a combination of a hard-stop closed-loopsealing rib 324 and a compliant closed-loop sealing rib 124 can be used.

In accordance with this alternative embodiment, as the flexiblesubstrate 114 collapses, under predetermined pressure, into the walledaperture 108 against the bottom surface 110, the closed-loop hard-stopsealing rib 324 seals against the flexible substrate 114 in conjunctionwith the compliant closed-loop sealing rib 124 sealing against thebottom surface 110 of walled aperture 108, thereby isolating thebreathable membrane 118. The closed-loop sealing ribs 124 and 324 limittravel of the flexible substrate 114, thereby protecting the substratesurfaces, while providing a seal.

The embodiments provided thus far provide for a venting and sealingassembly wherein the breathable membrane provides a passive pressureequalization vent mounted in series with the moveable substrate whichoperates as an active sealing valve mechanism.

In another alternative embodiment, shown in FIG. 4, a breathablemembrane provides a passive pressure equalization vent to a moveablerigid substrate separated by a vent passage across from an interiorstationary flexible substrate. FIG. 4 is a partial cutaway view of aventing and sealing assembly 400 in accordance with this alternativeembodiment.

Assembly 400 comprises a housing 406 having a moveable substrateportion, formed of a rigid material. The rigid material may be formed,for example, of the same or similar material to that as the housing 406,such as a hard plastic or other water impermeable material. Inaccordance with this embodiment, flexure bellows 420 or other flexibleinterconnect means, enable movement of the rigid substrate portionrelative to the housing 406 and will therefore be referred to asmoveable rigid substrate 414. A vent hole 416 is formed in the moveablerigid substrate 414 for venting between an interior 460 and an exterior450 of the housing 406. The exterior 450 of the housing 406 is sometimesreferred to as the wet side of the radio, while the interior of thehousing 406 is sometimes referred to as the dry side.

In accordance with this embodiment, a breathable membrane 418 is coupledacross the vent hole 416 of the moveable rigid substrate 414. Thebreathable membrane 418 is coupled across the vent hole 416 of themoveable rigid substrate 414 and adhesively coupled to the moveablerigid substrate 414 with an adhesive layer 417. The adhesive layer 417has a cut-out which aligns with the vent hole 416 of the moveable rigidsubstrate 414. The adhesive layer 417, may be a pressure sensitiveadhesive (PSA), such as a very high bond (VHB) adhesive or othersuitable adhesive.

An internal rib sealing surface is provided by a flexible substrate 410having a compliant sealing rib 424 formed thereon. The flexiblesubstrate 410 is stationarily coupled within a walled aperture 408formed within the housing 406. In accordance with the embodiment, thevent hole 416 of the moveable rigid substrate 414, covered by breathablemembrane 418 opens into the walled aperture 408 across from the flexiblesubstrate. The closed-loop sealing rib 424 is aligned and beneath themoveable rigid substrate 414 around the breathable membrane 418. Inaccordance with an embodiment, the moveable rigid substrate 414(exterior movable surface) has a wider surface area than the flexiblesubstrate 410 that provides the internal rib sealing surface (interiorsealing surface). The use of the moveable rigid substrate 414 on theouter surface provides the stiffness backing in a similar manner to thatof the rigid plate 120 in the previous embodiments, while the flexiblesubstrate 410 is located in the interior side 460.

In response to predetermined changes in pressure being sensed betweenthe interior 460 and the exterior 450 at the vent hole 416 by therestrictive properties of the breathable membrane 418, the moveablerigid substrate 414 is pulled into the walled aperture 408 against theclosed-loop sealing rib 424 of the flexible substrate 410 therebyisolating the breathable membrane 418.

In normal use mode, the vent path 402 is formed between the exterior450, the breathable membrane 418 covering the vent hole 416 of themoveable rigid substrate 414, the walled aperture 408, through theoffset vent-hole 412 into interior 460. In sealing mode, the vent path402 becomes sealed in response to the predetermined pressure (pressuremode) pulling the breathable membrane 418 coupled across the vent hole416 of the moveable rigid substrate 414 across the closed-loop sealingrib 424 of the flexible substrate 410. Thus, venting and sealing havebeen provided by the embodiment of FIG. 4.

In accordance with an embodiment, the vent hole 416 of the moveablerigid substrate 414 may extend into a drainage cone 428 formed into themoveable rigid substrate for water drainage. Alternatively, the moveablerigid substrate 414 may extend straight out the vent hole 416, similarlyto the opening 122 of the rigid plate 120 of the other previouslydescribed embodiments.

Accordingly, there has been provided, a substrate (flexible or rigid)that moves against a bottom surface of a walled aperture of a housingand seals using a closed loop sealing rib thereby isolating a breathablemembrane coupled to the moveable substrate. The internal sealing riblimits travel of the moveable substrate within the interior walledaperture for sealing a vent passage.

The closed loop sealing rib may be formed on the interior surface of oneor both of: a moveable flexible substrate 114, such as was shown bysealing rib 124, and an interior stationary bottom surface 110, such aswas shown by sealing rib 324. The closed loop sealing rib 424 may alsobe formed on an interior stationary bottom flexible substrate 410.

For a normal use case, in each of the embodiments, force and deflectioncharacteristics of the moveable outer substrate (flexible 114, 214 orrigid 414 outer substrate) and positioning of the one or more interiorclosed-loop ribs (124, 224, 324, 424) provide for the valve mechanism.For a pressure use case: the movable substrate (flexible 114, 214 orrigid 414) collapses into the walled aperture such that the closed looprib seals the bottom surface, thereby isolating the breathable membrane(118, 218 or 418). In other words the pressure use case isolates thepassive pressure equalization vent.

The self-pressure equalization provided by the assembly provides forautomatic venting and sealing. The venting and sealing assembly is easyto test in that the breathable membrane 118, 218, 318, 418 need not beremoved from the radio system prior to vacuum test, eliminatingpost-test alignment issues. A vacuum test can be performed duringassembly of the product as opposed to just the membrane, thusadvantageously allowing for the detection of even small leaks. Nodisabling of the breathable membrane, such as with water, is needed,during testing, thereby facilitating testing in a dry environment.Accordingly, there has been provided a waterproof venting and sealingsystem incorporated into a single portable communication device having alimited spatial form factor.

Any communication device where ruggedness and good sealing in a smallform factor are desired can benefit from the venting and sealingassembly apparatus of the various embodiments.

In the foregoing specification, specific embodiments of the presentinvention have been described. However, one of ordinary skill in the artappreciates that various modifications and changes can be made withoutdeparting from the scope of the present invention as set forth in theclaims below. Accordingly, the specification and figures are to beregarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope ofpresent invention. The benefits, advantages, solutions to problems, andany element(s) that may cause any benefit, advantage, or solution tooccur or become more pronounced are not to be construed as a critical,required, or essential features or elements of any or all the claims.The invention is defined solely by the appended claims including anyamendments made during the pendency of this application and allequivalents of those claims as issued.

1. A venting and sealing assembly, comprising: a housing enclosurehaving a walled aperture with a bottom surface and an offsetthrough-hole passing therethrough; a flexible substrate having a venthole, the flexible substrate being coupled to the housing enclosureacross the walled aperture such that the vent hole is offset from theoffset-through-hole; a breathable membrane coupled across the vent holeof the flexible substrate; a rigid plate having an opening coupled tothe breathable membrane, the opening of the rigid plate being alignedwith the vent hole of the flexible substrate; and a closed-loop sealingrib formed upon at least one of: the flexible substrate, around the venthole; the housing enclosure, upon the bottom surface of the walledaperture.
 2. The venting and sealing assembly of claim 1, wherein theflexible substrate is moveable relative to the housing enclosure toprovide venting and sealing of the assembly.
 3. The venting and sealingassembly of claim 1, wherein the closed-loop sealing rib seals theflexible substrate with the housing enclosure in response to changes inpressure.
 4. The venting and sealing assembly of claim 1, wherein a ventpath is formed through the offset through-hole of the housing enclosure,the walled aperture of the housing enclosure, the vent hole of theflexible substrate, the breathable membrane coupled across the vent holeof the flexible substrate and the opening of the rigid plate.
 5. Theventing and sealing assembly of claim 1, wherein the rigid plateprovides an external rigid surface area that is larger than an internalsealing area created by the closed-loop sealing rib.
 6. The venting andsealing assembly of claim 1, wherein the closed-loop sealing ribcomprises at least one of: a compliant closed loop sealing ribintegrated with the flexible substrate around the vent hole; a hard-stopclosed loop sealing rib integrated with the housing enclosure, upon thebottom surface of the walled aperture.
 7. The venting and sealingassembly of claim 1, wherein the breathable membrane provides a passivepressure equalization vent mounted in series with the flexible substratewhich operates as an active sealing valve mechanism.
 8. The venting andsealing assembly of claim 7, wherein the rigid plate provides gain tothe active sealing valve mechanism sealing pressure to securely isolatethe passive pressure equalization vent.
 9. The venting and sealingassembly of claim 1, wherein the flexible substrate operates as anactive sealing valve mechanism to form a waterproof barrier over thewalled aperture of the housing enclosure.
 10. The venting and sealingassembly of claim 1, wherein the closed-loop sealing rib limits travelof the flexible substrate.
 11. The venting and sealing assembly of claim2, wherein force and deflection characteristics of the flexiblesubstrate and positioning of the closed-loop sealing rib is tuned asfollows: for a normal use case: the assembly behaves as a passivepressure equalization vent; and for a pressure use case: the flexiblesubstrate collapses into the walled aperture such that the closed looprib seals against the bottom surface, thereby isolating the breathablemembrane. 12.-20. (canceled)
 21. The venting and sealing assembly ofclaim 1, wherein the closed-loop sealing rib is formed around the venthole upon two sides of the flexible substrate.